August 17, 2023

tRowGenerator – Docs for ESB 5.x

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tRowGenerator

tRowGenerator.png

tRowGenerator properties

Component family

Misc

  

Function

tRowGenerator generates as many
rows and fields as are required using random values taken from a
list.

Purpose

It can be used to create an input flow in a Job for testing
purposes, in particular for boundary test sets

Basic settings

Schema and Edit
schema

A schema is a row description, it defines the number of fields to
be processed and passed on to the next component. The schema is
either built-in or stored remotely in the Repository.

Click Edit schema to make changes to the schema. If the
current schema is of the Repository type, three options are
available:

  • View schema: choose this option to view the
    schema only.

  • Change to built-in property: choose this option
    to change the schema to Built-in for local
    changes.

  • Update repository connection: choose this option to change
    the schema stored in the repository and decide whether to propagate the changes to
    all the Jobs upon completion. If you just want to propagate the changes to the
    current Job, you can select No upon completion and
    choose this schema metadata again in the [Repository
    Content]     window.

 

 

Built-in: You create and store
the schema locally for this component only. Related topic: see
Talend StudioUser
Guide.

 

 

Repository: Select the Repository
file where the properties are stored. When selected, the fields that
follow are filled in automatically using fetched data.

 

RowGenerator editor

The editor allows you to define the columns and the nature of data
to be generated. You can use predefined routines or type in the
function to be used to generate the data specified.

Note that in a Storm Job, the value -1 in the Number
of rows for RowGenerator field in the RowGenerator editor means to generate
infinite rows of input data.

Advanced settings

tStatCatcher Statistics

Select this check box to collect log data at the component
level.

Global Variables

NB_LINE: the number of rows processed. This is an After
variable and it returns an integer.

ERROR_MESSAGE: the error message generated by the
component when an error occurs. This is an After variable and it returns a string. This
variable functions only if the Die on error check box is
cleared, if the component has this check box.

A Flow variable functions during the execution of a component while an After variable
functions after the execution of the component.

To fill up a field or expression with a variable, press Ctrl +
Space to access the variable list and choose the variable to use from it.

For further information about variables, see Talend Studio
User Guide.

Usage

The tRowGenerator Editor’s ease
of use allows users without any Java knowledge to generate random
data for test purposes.

Usage in Map/Reduce Jobs

In a Talend Map/Reduce Job, it is used as a start component and requires
a transformation component as output link. The other components used along with it must be
Map/Reduce components, too. They generate native Map/Reduce code that can be executed
directly in Hadoop.

You need to use the Hadoop Configuration tab in the
Run view to define the connection to a given Hadoop
distribution for the whole Job.

This connection is effective on a per-Job basis.

For further information about a Talend Map/Reduce Job, see the sections
describing how to create, convert and configure a Talend Map/Reduce Job of the
Talend Big Data Getting Started Guide.

Note that in this documentation, unless otherwise explicitly stated, a scenario presents
only Standard Jobs, that is to say traditional Talend data
integration Jobs, and non Map/Reduce Jobs.

Usage in Storm Jobs

In a Talend Storm Job, it is used as a start component. The other
components used along with it must be Storm components, too. They generate native Storm code
that can be executed directly in a Storm system.

The Storm version does not support the use of the global variables.

You need to use the Storm Configuration tab in the
Run view to define the connection to a given Storm
system for the whole Job.

This connection is effective on a per-Job basis.

For further information about a Talend Storm Job, see the sections
describing how to create and configure a Talend Storm Job of the Talend Big Data Getting Started Guide.

Note that in this documentation, unless otherwise explicitly stated, a scenario presents
only Standard Jobs, that is to say traditional Talend data
integration Jobs.

Log4j

The activity of this component can be logged using the log4j feature. For more information on this feature, see Talend Studio User
Guide.

For more information on the log4j logging levels, see the Apache documentation at http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/Level.html.

Limitation

n/a

The tRowGenerator Editor opens up on a separate
window made of two parts:

  • a Schema definition panel at the top of the
    window

  • and a Function definition and preview panel
    at the bottom.

Defining the schema

First you need to define the structure of data to be generated.

  • Add as many columns to your schema as needed, using the plus (+) button.

  • Type in the names of the columns to be created in the Columns area and select the Key check box if required

  • Make sure you define then the nature of the data contained in the column,
    by selecting the Type in the list.
    According to the type you select, the list of Functions offered will differ. This information is therefore
    compulsory.

Use_Case_tRowGeneratorSchema.png

  • Some extra information, although not required, might be useful such as
    Length, Precision or Comment. You
    can also hide these columns, by clicking on the Columns drop-down button next to the toolbar, and unchecking
    the relevant entries on the list.

  • In the Function area, you can select the
    predefined routine/function if one of them corresponds to your needs.You can
    also add to this list any routine you stored in the Routine area of the Repository. Or you can type in the function you want to use
    in the Function definition panel. Related
    topic: see Talend Studio User Guide.

  • Click Refresh to have a preview of the
    data generated.

  • Type in a number of rows to be generated. The more rows to be generated,
    the longer it’ll take to carry out the generation operation.

Defining the function

Select the […] under Function in the Schema definition panel in order to customize the
function parameters.

  • Select the Function parameters tab

  • The Parameter area displays Customized parameter as function name
    (read-only)

Use_Case_tRowGeneratorFunctionCust.png

  • In the Value area, type in the Java
    function to be used to generate the data specified.

  • Click on the Preview tab and click
    Preview to check out a sample of the
    data generated.

Scenario: Generating random java data

The following scenario creates a two-component Job, generating 50 rows structured as
follows: a randomly picked-up ID in a 1-to-3 range, a random ascii First Name and Last
Name generation and a random date taken in a defined range.

Use_Case_tRowGenerator1.png

  • Drop a tRowGenerator and a tLogRow component from the Palette to the design workspace.

  • Right-click tRowGenerator and select
    Row > Main. Drag this main row link onto the tLogRow component and release when the plug symbol
    displays.

  • Double click tRowGenerator to open the
    Editor.

  • Define the fields to be generated.

Use_Case_tRowGenerator2.png

  • The random ID column is of integer type, the First and Last names are of
    string type and the Date is of date type.

  • In the Function list, select the relevant
    function or set on the three dots for custom function.

  • On the Function parameters tab, define the
    Values to be randomly picked up.

Use_Case_tRowGenerator3.png

  • First_Name and Last_Name columns are
    to be generated using the getAsciiRandomString function that is predefined in
    the system routines. By default the length defined is 6 characters long. You can
    change this if need be.

  • The Date column calls the predefined getRandomDate
    function. You can edit the parameter values in the Function parameters tab.

  • Set the Number of Rows to be generated to
    50.

  • Click OK to validate the setting.

  • Double click tLogRow to view the Basic
    settings. The default setting is retained for this Job.

  • Press F6 to run the Job.

Use_Case_tRowGenerator4.png

The 50 rows are generated following the setting defined in the tRowGenerator editor and the output is displayed in the Run console.

Document get from Talend https://help.talend.com
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Docs 5.x
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